The effects of captopril and enalapril on tissue levels of various elements in spontaneously hypertensive rats.

The effects of two inhibitors of angiotensin I converting enzyme, captopril and enalapril, on the concentrations of Na, K, Ca, Mg, Fe, S, P, Sr, Mn, Cu and Zn ions in blood, plasma, heart, skeletal muscle, liver and kidney of spontaneously hypertensive rats (SHR) were studied. Captopril and enalapril were given by the intraperitoneal route for 15 days, at 160 mumols/kg/d and 40 mumols/kg/d, respectively. Elements in tissues were determined by inductively coupled plasma emission spectrometry with a JY 48 instrument. The common changes produced with the two drugs were: a decrease of Na in muscle (-10%), a decrease of Ca in plasma and kidney (less than -10%) and a decrease of Mn in liver (-15%). The main effects observed with only one of the two drugs were: an increase of Cu in plasma (+26%) with captopril, and increases of Sr in heart (+56%), muscle (+79%) and liver (+74%) with enalapril. Zinc concentration in tissues was not modified, except for an increase in liver with captopril (+13%) and a decrease in heart with enalapril (-11%).